In digital photography, images are typically formed by passing light from an object through an objective and infrared (IR) filter onto an image sensor or image capture unit such as a CMOS or CCD unit. The image capture unit typically comprises some millions of pixel sensing elements for forming corresponding pixels of digital images. Interlaced grids of red, green and blue pixel sensing elements form respectively colored pixels. Simply said, digital photography forms a brightness map of red, green and blue pixels evenly distributed throughout an image. In optimal conditions, the ambient light that illuminates the target is sunlight filtering through clouds so that the target is evenly illuminated by white light i.e. light that has an even visible light spectrum. Thus, the colors of the target can be accurately recorded by storing brightness values corresponding to signals produced by the different pixel sensing elements. However, often pictures are taken of targets illuminated by artificial light. Unfortunately, most artificial lights have a spectrum that significantly differs from natural light produced by the sun. Thus, the color spectrum of the image becomes biased and particularly the skin of people may appear unnatural to human eye. A vast number of different techniques are developed to address this problem. For example, the average or total brightness recorded can be calculated for all three different-colored pixel sensing elements and their balance can be used to deduce the probable source of light.